Motorcycle frame



FIG. 1 is a side view of a motorcycle frame.

FIG. 2 is a rear perspective view of the design shown in FIG. 1.

FIG. 3 is a front perspective view of the design shown in FIG. 1; and,

FIG. 4 is an enlarged perspective view of design shown in FIG. 1.

The broken line showing of the environment is for illustrative purposes only and forms no part of the claimed design. The broken lines which define the boundaries of the claimed design form no part thereof. 

We claim the ornamental design for a motorcycle frame, as shown and described. 